Link:  Pharm/Biotech Resources

Title:  Preparation consisting of a film, sheet or wafer-shaped form of administration with a two-layered structure and an integrated identification marking

United States Patent:  6,913,766

Issued:  July 5, 2005

Inventors:  Krumme; Markus (Neuwied, DE); Ludwig; Karin (Datzeroth, DE)

Assignee:  LTS Lohmann Therapie-Systeme AG (Andernach, DE)

Appl. No.:  129833

Filed:  November 3, 2000

PCT Filed:  November 3, 2000

PCT NO:  PCT/EP00/10862

371 Date:  July 10, 2002

102(e) Date:  July 10, 2002

PCT PUB.NO.:  WO01/35931

PCT PUB. Date:  May 25, 2001

A sheet-like, film-like or wafer-like preparation for administering substances affecting flavor or odor and/or substances for care and/or curative substances, comprising a coding of these substances in the form of characters and/or graphic symbols or patterns, with the coding being formed by surface areas of differing thickness, is characterized in that the preparation comprises two differently colored, adjacent layers which have surface areas of differing thickness which are complementary to each other.

SUMMARY OF THE INVENTION

It was therefore the object of the present invention to provide a preparation having an administration form which is in the form of a sheet, a film or a wafer, and which contains at least one substance from the group consisting of flavors, odorants, therapeutic substances and curative substances, which preparation is provided with an identification or coding in the form of characters, signs/symbols or patterns, but which does not have the disadvantages of the administration forms known from the prior art. It was furthermore an object of the invention to indicate processes which enable a simple and economical manufacture of the administration forms according to the present invention.

Surprisingly, this object is achieved in that flat-shaped, in particular sheet-like, film-like or wafer-like preparations, possess a two- or multi-layered structure, where two adjacent layers are of different colour and/or have surface areas of differing thickness which are complementary (or reciprocal) to each other.

DETAILED DESCRIPTION OF THE INVENTION

The term "of differing thickness" refers to differences in thickness within a respective layer of the two layers. Thus, the double-layered preparations according to the invention can also possess surface areas where the two layers are of the same or almost the same thickness.

By means of the patterned thickness differences in the layers of the sheet-like, film-like or wafer-like administration forms, an identification marking is accomplished in the surface of the preparation which is visible to the eye and is similar in its effect to a watermark in a paper-like dispersion.

Because of the special arrangement of two layers which are of complementary shape and of different colour the visual perceptibility of the symbols or patterns, which are produced by the thickness gradients, is considerably improved. A further advantage results from the manifold combinations of colours, it being possible to further increase the perceptibility by appropriate selection of colours (e.g. complementary colours). To produce an optimal visual effect it may be of advantage for the layers to be essentially opaque. In particular cases it may also be advantageous to use transparent layers. The identification markings may be letters, numbers, symbols, logos, pictographs or figurative representations.

The difference in colour of the two layers may be accomplished by differences in terms of colour tone, colour saturation or colour brightness, or by combinations of these parameters. The colours black, white, as well as grey colour tones are also understood as being colours in the sense of the invention. Furthermore, embodiments are also encompassed where one of the two layers is made to be clear-transparent. Since the visual effect is brought about mainly by refraction of light at the phase boundaries of the two layers, minor differences in the colour tone, in the colour saturation or the brightness may cause that the contours of the symbols or patterns, which serve as a coding, are clearly perceptible. In addition, the surface areas of the identification markings, symbols or patterns located inside or, respectively, outside the contours also contrast with each other, on account of the differences in colour tone or colour saturation or colour brightness. Moreover, due to two surface areas of differing thickness and different colour overlying each other, each time two new colours or shades are produced which result from either the one or the other layer being thinner or thicker in the region of overlap. In this way, the perceptibility of the marks or patterns, which are formed as thickness gradients in the two layers, is further enhanced.

In comparison to the conventional, watermark-like identification markings, whose perceptibility is due merely to minimal light/dark contrasts, the present invention makes use of the advantageous properties of colour contrasts. In addition, light-dark contrasts occur here which contribute to the perceptibility of the identification markings. Since the identification according to the present invention-as with conventional watermark-like markings or embossings-also constitutes a coding which is an integral and inseparable part of the pharmaceutical preparation itself, it also offers the advantages resulting therefrom (e.g. proofness against forgery) which are not present in other coding methods, especially in printing.

Especially for medicine forms consisting of thin layers (e.g. film-like or wafer-like administration forms) the type of marking or coding according to the present invention is an advantageous alternative compared to the known methods. Producing identifying patterns or symbols by interaction of two complementary, differently coloured layers not only improves recognizability, but also opens up numerous new possibilities of variation in representation.

Since the layer thickness is substantially constant over the entire surface, it is possible to accomplish optimal loading with active substance. The double-layered structure furthermore enables loading with different active substances or other, different substances of the kind mentioned in the introductory portion of claim 1. Further possibilities result from the fact that the two layers can in different ways be provided with additives which have an effect on the release behaviour.

For certain application purposes it may be useful, or necessary, to equip the double-layered administration form of the present invention with further layers. In order not to interfere with the perceptibility of the coding, layers are preferred here that are essentially transparent.

In one embodiment of the invention the surface areas of differing thickness, especially in the layer that is produced first, are formed under the production conditions while avoiding differences in density or compression. This is preferably achieved by forming the surface areas of differing thickness of the first layer without the action of pressure. Thereafter, the second layer is applied to the first layer in such a manner that it completes the relief-like thickness differences pre-formed in the first layer in a complementary manner.

According to another embodiment of the invention the portions of differing thickness, especially those of the layer which is produced first, are of differing density or compression due to the process of manufacture. This can be accomplished by applying the symbols or patterns of the coding in the already pre-fabricated first layer under action of pressure.

The method according to the invention for producing the preparation involves the symbols or patterns serving as the coding being introduced into the first layer by irreversible deformation in the plastically deformable state.

To produce the areas of differing thickness without action of pressure, the mass used for making the layer is coated onto a support, which has a sequence of depressions and elevations corresponding to the coding (identifying marking or pattern). Such depressions or elevations can be arranged, for example, on a support similar to a pressure or printing plate by grinding or etching.

To accomplish the areas of differing thickness in the first layer without the action of pressure, it is possible to use, for example, appropriately structured embossing rollers or stamps.

When the first layer, with relief-like areas of differing thickness, has been produced, whether with or without action of pressure, the second layer is applied by coating from the solution or melt, namely on that side of the first layer which has the relief-like depressions and elevations. The coating mass used to make the second layer must be selected such that on the one hand it enables good anchorage of the second layer onto the first, structured layer, but on the other hand does not dissolve or melt the first layer.

The term "coating" is understood to refer to any manner of applying a hardenable liquid mass on a carrier by means of knife application, roller application, extrusion or spraying processes.

A further method according to the invention for providing the first layer with pattern-like thickness gradients consists in subjecting the preparation to local temperature differences during drying. This can be accomplished by selectively delivering heated air, with the layer to be dried being located on a support which has a lattice-like pattern or consists of materials with different heat conduction which are so arranged that they can form patterns or identifying markings. By exposure to local temperature differences, thickness differences are produced in the layer in such a way that the material in the warmer zones is thicker and the material in the colder zones is thinner. The temperature differences that may occur locally between the warmer and the colder zones are within a range of 10-100° C., preferably between 30-80° C.

The methods according to the invention may be adapted so as to be continuous or discontinuous. Discontinuous manufacture may, for example, be accomplished by conveying the plastically deformable mass on an adhesively treated conveyor belt and in the process providing it with a marking or pattern for coding by means of a structured embossing roller or by exposure to local temperature differences. Subsequently, the second layer is applied by way of a likewise continuous application process (doctor knife, rollers).

In the case of a discontinuous or intermittent method of manufacture, the coating mass of the first layer may be applied on a correspondingly structured support having a pre-determined area. Alternatively, the markings, patterns or symbols serving as a coding may also be introduced in the plastically deformable first layer by means of a stamp. After hardening thereof, the mass for the second layer is applied to that side of the first layer which is provided with relief-like elevations and depressions, using one of the coating methods mentioned.

In the following, the production of coded, flat-shaped administration forms, i.e. flat-shaped administration forms provided with thickness differences in the form of identifying marks, patterns or symbols, will be explained in more detail by way of examples of embodiments. Here, I, II and III designate three different production methods. These methods involve a sequence of work steps A-E as follows:

A. Production of the Coating Mass

Combining individual components by mixing, dissolving, dispersing, suspending or emulsifying. The solvent, dispersing or suspension agent used is preferably an ethanol-water mixture, but other solvents or solvent mixtures which are readily withdrawable can also be used. An illustrative formulation of a coating mass, which is especially suitable for forming surface areas of differing thickness under action of pressure ("embossing method"), is:

Claim 1 of 16 Claims

1. A preparation for administering active substances comprising:

a first layer;

a second layer adjacent to the first layer, the second layer having a different color than the first layer; and

coding in the form of at least one of characters, graphic symbols or patterns for identifying the active substances, the coding being formed by surface areas having differing thicknesses in each of the first and second layers, and the surface areas of differing thicknesses of the first layer are complementary to the surface areas of differing thickness of the second layer;

wherein the preparation is a sheet, a film or a wafer.

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